1. Field of the Invention
This invention relates to a series of penicillins and in particular to 6-(phenyl- and thienylacetamido)penicillanic acids and esters which are substituted in the phenyl and thienyl moieties with an aminomethyl substituent, possessing high antibacterial activity, especially against such gram-negative microorganisms as E. coli and Klebsiella.
2. Description of the Prior Art
The compounds belonging to the family of penicillins differ from each other in the nature of the R variable and possess the general formula indicated below wherein the acyl moiety on the 6-aminopenicillanic acid ##STR1## is derived from a carboxylic acid or functional derivative thereof such as an acyl halide or anhydride.
The pharmacodynamic properties and antibiotic profile of a given penicillin are determined to a large extent by the nature of the R group. The most widely used penicillins are those wherein the R moiety is represented by benzyl-, phenoxymethyl- or .alpha.-phenoxyethyl-. While these well-known analogs are highly antagonistic toward gram-positive microorganisms they have limited gram-negative activity. Consequently, drugs which will combat a rise in gram-negative infections, e.g., E. coli, Pseudomonas or Klebsiella, are of value to the medical profession.
Recent efforts to improve the profile of activity within the family of penicillins have resulted in the synthesis of several new agents. 6-(p-Aminomethylphenylacetamido)penicillanic acid is claimed in British Pat. 1,057,029, while 6-(o-, m- and p-aminomethylphenoxyacetamido)penicillanic acids are described by Schorr, et al., Arch. Pharmaz., 304, 325 (1971). Aminomethyl substituted 7-(phenyl-, phenylthio- and phenoxyacetamido)cephalosporanic acid derivatives are described in U.S. Pat. Nos. 3,766,175; 3,766,176; 3,813,376, 3,813,390 and 3,813,391.